Lock washer and method of making same



May 21, 1935.

F. w; ENGLAND LOCK WASHER AND METHOD OF MAKING SAME Fi-led NOV. 24, 1933INVENTOR= FRANK w. ENGLAND ATT'YS.

Patented May 21, 1935' 2,001,956

UNITED STATES PATENT; OFFICE LOCK WASHER AND METHOD OF MAKING SAME FrankW. England, Chicago, Ill., assignor to Illinois Tool Works, Chicago,111., a corporation of Illinois Application November 24, 1933, SerialNo. 699,534

11 Claims. (01. 10-86) My invention relates generally to lock washersFigure 3 is a view of the external edge of the and methods of makingsame, and more particudevice of Figure 2; 7 larly to lock washers oi theoverlapping tooth Figure t is a fragmentary view of the internal type,and to improved methods of.making same. edge of the device in Figure 2,said view being I It is one of the primary objects of my invention takensubstantially along the line 44 of Fig- 5 to provide a washer of theoverlapping tooth type, ure 2; i namely, the type wherein adjacentradial mar- Figure 5 discloses the completed lock washer gins or prongsare disposed in overlapping relation, after the device of Figure 2 hasbeen reduced in by practicing simplified improved methods which diameterfor the purpose of producing the overbring about this overlappingrelationship. lapping relationship of-the adjacent margins of 10 "Moreparticularly, it is an object of my inventhe prongs, the dotted circlesin this figure desigtion to provide methods of the type mentioned natingthe original inner and outer peripheries above wherein a washer blankmay be radially of the washer prior to the diameter reducing slitted topresent a plurality of prongs, and suboperation;

sequently reduced in diameter so as to bring about Figure 6 is afragmentary w Of the elite! 15' an overlapping relationship of adjacentradial edge of the washer of Fi 5 w n s Washer margins of the prongs. isclamped against a work piece, said view being More specifically, myinvention contemplates a taken substantially al the line of Figurewasher of the overlapping tooth type wherein cer- 5; and

tain of the overlapping prong margins extend in- Fi ur 7 is a frag y V wO t inner edge 20 wardly from the outer margin of the washer oi thewasher of Figure s V ew being taken stock, and certain others extendoutwardly from substantially along the line of Figure the inner marginof said stock. Referring now to the drawing more in detail The inventionfurther contemplates forming an wherein like u s have been p y toannular washer blank with radial inner and outer designate similar partsthroughout the Various 25 severances or. slits, then deflecting thesections of fi e t l be se n t a y invention e0ntem the stock on eachside of said slits in'opposite diplates the Production of a Washer fromannular rections so as to present a plurality of work en- W s e s, W c Iv designated gaging edges, and subsequently reducing the exerally by theletter A. This blank A is first raao temal diameter of the washer so asto bring about dielly slit s v d along t inner and Outer 36 I anoverlapping relationship of the deflected secmargins a n icat d inFigures 2 0 c u tions, thereby producing a washer having a pluso as topresent inner marginal prongs l0 and y of. overlapping prongs. outermarginal prongs l2. Each of the prongs It is a further object of myinvention to pro- 10 includes what I prefer to designate as a cenduce'amethod of making lock washers of the r body p r i n fla andapair ofradial marginal 35 above mentioned overlapping type whereby the sectionslllb. Likewise, each of the prongs l2 washer stock is subjected to aminimum amount includes a central body portion IM and oppo r strain anddistortion when the diameter of the sitely disposed m i sections Inwasher is reduced to produce the overlapping ures 2 to 4, inclusive, Ihave shown the marginal 40 eflect; and I propose to accomplish this byaltersections 10b and l2b deflected out of the plane 40 nately slittinginner and outer sections of the of the Wa 80 as to Present. a pluralityof annular washer stock. dial work engaging edges l4 positioned on op-The' foregoing and numerous other objects and Desite Sides of the Washery and disposed in advantages will be more apparent from thefolsubstantial parallelism with said body.

'45 lowing'detailed description when considered in After the marginalsections lb and l2b have connection with the accompanying drawing, beendeflected out of the normal plane of the W e e washer, I cause thestructure to be reduced in Figure 1 discloses an annular washer blankfrom diameter as indicated in Figure 5. By reason of which my improvedwasher is adapted to be made; the fact that the washer body isoriginally slit Figure 2 is an elevational view of the blank after adistance which is approximately equal to two- 50 the inner and outermargins thereof have been thirds of the radial width of the body, andfurprovided with radial slits and the metal disposed ther, in view ofthe deflecting of the stock adjaat each side of the slits has beendeflected in cent said slits, these sections lllb and I2]; assumeppposite directions out of the plane of the washer the overlappingrelationship shown in Figure 5 stock; when the washer structure issubjected to a force 5 which tends to reduce the diameter, said forceobviously being exerted in a radial direction toward the center of thewasher. Various devices or combination of devices may be employed toefiect the reduction in diameter to produce the overlapping prongeffect. For instance, the washer may be forced through a taperedaperture, or it may be placed in a die having a plurality of inwardlyextending jaws similar to a work holding chuck used in a lathe, or itmay be placed in a die which operates by a draw-in collet of a lathe,which is simply a die made up of a plurality of members forming acylindrical nest in a ring, and tapered on the outside to fit a taperedhole or seat in the ring. In view of the fact that the present inventionis not concerned with the specific form of dies, punches, and the like,which may be employed in practicing my improved method, no illustrationis made of .these devices. It will suflice to say, however, that theinvention contemplates the use of various forms ofdevices whereby myimproved method of producing washers of the overlapping type maybeemployed. In Figure 5 I have indicated by dotted lines the originalinner and outer diameters of the washer prior to the step of reducingthe diameter to produce the overlapping effect.

Particular attention is directed to the fact that when my improvedmethod is practiced, the metal is subjected to little strain ordistortion as compared with methods wherein a continuous annular ringorbody must be compressed to eflect a reduction in diameter. In otherwords, by having prongs positioned along both the inner and outermargins of the washer in the manner described, the entire structure maybe reduced in diameter without subjecting the main body of the washer tocompression. The fact that the prong sections lllb and I 2b are inposition to slide over one another when force is applied to the outerperiphery of the washer in an inner radial direction, precludes thenecessity of subjecting the main body of the washer stock to anycompres-- sive. or deleterious strains. It will also be noted that theoriginal thickness of the washer stock is maintained in the main body ofthe washer. No stretching or expansion of the metal takes place,although ii-reduction in diameter is experienced. Having a plurality ofwork engaging edges spaced from and arranged in substantial parallelismwith the main body of the washer along the inner and outer margins asshown in Figure 5, presents a washer having increased lockingeffectiveness. The fact that the work engaging edges extend a radialdistance which is substantially equal to two-thirds r01 the normalradial width of the washer, increases the effective locking areaascompared with other types of pronged lock washers with which I amfamiliar. It may be stated that the work engaging edge of one prongextends into the body of the other prong. In other words, a workengaging edge provided on one of the inner prong sections lflb extendsoutwardly a radial distance suiiicient to encroach upon the body portionIn of the prongs l2. Similarly, the work engaging edges of the outerprong sections I211- extend into the body portion Illa of the prongs Hi.This arrangement, in effect, imparts a. zigzag configuration to theportion of the washer which is unslit.

My invention is in no sense limited to the specific structural featuresset forth herein, but is capable of other modifications and changeswithout departing from the spirit and scope thereof.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is:

1. A lock washer including an annular body of fiat spring stock providedwith a plurality of inner and outer marginal prongs, each prong having amarginal section overlapping the marginal section of an adjacent prong,whereby to present a plurality of inner and outer overlapping prongsections having work engaging edges positioned on opposite sides of amedian plane of the washer, each prong being substantially uniform inthickness.

2. A lock washer including an annular body of fiat spring stock providedwith a plurality of inner and outer marginal prongs, each prong having amarginal section overlapping the marginal section of an adjacent prong,whereby to present a plurality of inner and outer overlapping prongsections having. work engaging edges positioned on opposite sides of amedian plane of the washer, said washer being of substantially uniformthickness throughoutits extent.

3. A lock washer including an annular body 01' fiat spring stockprovided with a plurality of inner and outer marginal prongs, each pronghaving a marginal section overlapping the marginal section of anadjacent prong, whereby to present a plurality of inner and outeroverlapping prong sections having work engaging edges positioned onopposite sides of a median plane 012 the washer, said edges lying inplanes substantially parallel with said median plane, each prong beingsub- 1 stantially uniform in thickness.

4. A lock washer including an annular body of fiat spring stock providedwith a plurality of inner and outer marginal prongs, each prong having amarginal section overlapping the marginal section of an adjacent prong,whereby to present a plurality of inner and outer overlapping prongsections having work engaging edges positioned tion of an adjacentprong, whereby to presenta plurality of inner and outer overlappingprong sections having work engaging edges positioned on opposite sidesof a median plane of the washer, said edges extending a radial distancewhich is I greater than half the-radial width of the *washer body, saidprongs being of substantially the original consistency of the stock.

6. The method of producing lock washers which consists in radiallysevering inner and outer marginal portions of an annular body of springstock, maintaining the washer in a flattened state, and reducing theouter diameter of the body to produce an overlapping relationship of theportions of the stock on opposite sides of the severances withoutaiiecting the original thickness of the main body of the stock.

7. The method of producing lock washers which consists in radiallysevering marginal portions of an annular body of spring stock, causing.sections of the stock on each side of the severances to be deflected outof a median plane of a washer body so as to present a plurality ofoppositely disposed work engaging edges, maintaining the washer in aflattened state, and reducing the outer diameter aoonose o'! the body toproduce an overlapping relationship of the portions 01' the stock onopposite sides of the severances without aflecting the originalthickness of the main body of the stock.

' 8. The method of producing lock washers which consists in radiallysevering the inner and outer margins of an annular body of spring stock,and reducing the diameter of the body to produce an overlappingrelationship of the stock positioned on opposite sides of saidseverances.

v 9. A look washer including an inner series and outer series ofannularly arranged prongs of spring stock. those of each series beingdisposed in overlapping "relation, said prongs being of substantiallytheoriginal consistency of the stock.

l0. vThe method of making lock washers which includes the steps 0!providing radial severances along the inner and outer margins of annulara 3 spring stock, warping said prongs so as to presentopposltely'disposed work engaging edges. circumierentially shiftingadjacent radial margins of each prong so as to efiect the overlapping ofsaid margins without affecting the uniform thickness of the prongsduring said shitting.

11. The method of making lock washers which includes the steps offorming a plurality of inner and outer prongs along the inner and outermargins of annular flat spring stock, warpingsaid prongs to present workengaging edges on opposite sides of the medial plane of said flat stock.maintaining the roots of said prongs within the medial plane of saidfiat'stock, and causing adjacent margins of each pair of prongs to bedisposed in overlapping relation while maintainin the body of each pronguniform in thickness.

' FRANK W. ENGLAND.

